Inflatable structure



Nov. 21, 1967 J. P. KWAKE INFLATABLE STRUCTURE- Original Filed May 25,1965 United States Patent 3,353,309 INFLATABLE STRUCTURE John P. Kwake,2507 Carob Drive, Los Angeles, @alif. 90046 Continuation of applicationScr. No. 458,669, May 25, 1965. This application Feb. 13, 1967, Ser. No.615,839 16 Claims. (Cl. 52-2) This patent application is a continuationof patent application Ser. No. 458,609, filed May 25, 1965, nowabandoned.

This invention relates to dome type structures, and more particularly toa unique inflatable structure and associated control means therefor toprovide a temporary enclosure over the top of another structure.

The invention has particular utility and will be described in use forswimming pools, but it will be apparent that it is useful to provide adome-like covering for any structure.

Dome or hut type shells of rigid construction are known for use overswimming pools. Such structures are par ticularly advantageous duringthe fall and winter months, as they prevent leaves, dirt and snow fromblowing or falling into the pool. Also, those that are not made of metalare effective to reduce heat loss from a heated pool so that persons canenjoy swimming in comfort and at times when it would otherwise beeconomically prohibitive to heat the pool.

However, such rigid structures have several disadvantages. One drawbackis that they cannot readily be removed during warm months, when it ispreferred to swim outdoors. If they are removed, they cannot be storedin a small space. Also, the materials of which they are made areadversely affected by the water that is in the air directly above thepool. In this latter connection, considerable amounts of water condenseon the inner walls of the shell, causing them to rust if they are formedof metal, or to rot if they are made of wood and/0r plasterconstruction.

In order to avoid the use or rigid structures and to employ, instead, areadily inflatable and deflatable, (and thereby readily assembleable anddisassembleable) structure unsupported plastic domes, tied down at thecorners have been used, in the past, to enclose swimming pools and otherareas. Such domes have been pressurized by air at a pressure slightly inexcess of atmospheric pressure. Such plastic domes were made ofreinforced plastic because non-reinforced plastic domes, tied down atthe corners, might tear under high wind loadings. Such reinforcedplastic domes are very costly, and in addition, reinforced plastics arenot manufactured in a glass clear condition. Additionally, pressurecontrol in the inflatable structures of the prior art was not simple,economical and eflicient.

In view of the foregoing, it is a major object of the present inventionto provide an unsupported, inflatable dome-like structure made of a lowcost, non-reinforced, sheet plastic having stabilizing and spacedreinforcing means preventing shifting even under high wind loadings, andpreventing tearing of the plastic.

It is another object of the present invention to provide a pressurecontrol means that is simple, economical, and efficient for regulatingthe pressure within an inflatable air structure made of a non-rigidmaterial, such as flexible plastic sheet.

It is an object of my invention to provide a unique inflatable structuresuitable as a temporary covering for another structure, which providesall the advantages but none of the disadvantages of the prior art.

It is another object of my invention to provide a unique inflatableshell structure with means for keeping it in- 3,3535%? Patented Nov. 21,1'96? flated, but which can easily be deflated and removed and stored ina minimum of space.

A further object of my invention is to provide an inflatable structuresuitable for use over a swimming pool, and which will not be adverselyaffected by water.

It is also an object of my invention to provide a unique inflatableshell structure comprising a minimum number of component parts of simpledesign and rugged construction.

The above and other objects and advantages of my invention will becomeapparent from the following descrip tion taken in conjunction with theaccompanying drawings of an illustrative embodiment thereof, in which:

FIGURE 1 is a perspective view of an inflated plastic cover of myinvention in position over a swimming pool, showing a blower assemblypositioned at one end for supplying air to the interior of the cover,and showing the connection of a cord from the top of the cover to a barfor operating the control switch for the motor of the blower;

FIGURE 2 is a side elevational view of the blower assembly and afragmentary sectional view of the portion of the inflatable cover intowhich air is introduced from the blower;

FIGURE 3 is a fragmentary sectional view taken along the line 33 ofFIGURE 2;

FIGURE 4 is an enlarged fragmentary sectional view of the like numberedarea indicated in FIGURE 2;

FIGURE 5 is a top plan view of the portion of the top of the plasticcover to which the switch control cord is connected, showing areinforced plastic disc fused around its edge to the body of the cover,and showing how the line is connected through the disc;

FIGURE 6 is an enlarged fragmentary sectional view taken along the line66 of FIGURE 5;

FIGURE 7 is a fragmentary sectional view taken along the line 7.7 ofFIGURE 1, showing how guy lines are connected between support pins inthe pool decking and the ends of reinforced plastic strips that aremolded to the outer surface of the plastic cover, and showing in greaterdetail the construction of the waterfilled tubular rim of the cover;

FIGURE 8 is a fragmentary and elevational view of the portion of theinflated cover at which the door is located;

FIGURE 9 is an enlarged fragmentary sectional view of the doorconstruction taken along the line 9-9 of FIGURE 8;

FIGURE 10 is a schematic representation of a mercury switch meansuseable in my invention; and

FIGURE 11 is an enlargement of one corner of the door and door openingtaken from FIGURE 8.

Referring to FIGURE 1, an inflatable structure 10 of my invention isshown in its inflated position over a swimming pool 11. The body of thecover 10 is shown to have an opaque top or ceiling portion 12, and acontinuous wall portion 13 that is transparent. The lower edge of thewall 13 is formed of a tubular rim 14 which rests on the decking 15surrounding the pool 11. The entire cover 10, i.e., the ceiling portion12, the wall 13 and the tube 14, preferably is made of foldable plasticmaterial, which may be any suitable non-porous thermosetting orthermoplastic material. One such pool cover I have made is made entirelyof a vinyl plastic (such as polyvinylchloride or polyvinylacetate), inwhich the ceiling portion 12 and the tube 14 are made of opaque vinylplastic, and the wall 13 is made of transparent vinyl plastic fused atits upper edge to the ceiling portion 12 and at its lower edge to thetube 14. Another construction is one which both the ceiling portion 12and the Wall 13 are constituted of a single piece of transparent vinyl.

The tube 14 is a weighted member. Preferably the tube is formed as acontinuous tube, as by fusing the ends of an elongated tube together,and is provided with fitting through which the tube can be filled withwater. As best seen in FIGURE 7, a fitting 16 is cemented or otherwisesuitably secured in the wall of the tube 14, and is provided with a cap17. The fitting 16 is located outwardly of the lower edge of the wall13, which, as shown, is formed with an outer lip or flange 18 that isfused to the top portion of the tube 14. Water filling the tube forcesits lower surface into sealing contact with the decking 14, so that airdoes not escape beneath the tube. The elongated tube may also be formedof a plurality of elongated contiguous tube sections, each with its ownfilling port, and such plurality of tube sections will form a continuoustube, functionally speaking.

The cover at one end is provided with a door 21 shown as a generallysemicircular element which is fused along its straight edge to areinforced plastic strip 22 that is itself fused to the wall 13. Thecurved portion of the door 21 is provided with a reinforced plasticstrip 23 fused thereto, which is adapted to fit against a similarreinforced strip 24 that is fused to the wall 13. A handle 25 isprovided for locking the door in place against the reinforced strip 24.The strips 22-24 may, for example, be formed of nylon-reinforced vinylstrips.

At the opposite end of the cover 10 is a blower assembly through whichair is forced into the interior of the cover. Referring to FIGURES 1-4,the blower assembly 30 contains a housing 31 for a blower fan (notshown) which is supported in a frame 32 held above the. ground as onsupport legs 33. A motor 34 is mounted on the fan housing 31, and aswitch 35 is connected between motor leads 36 and an electric cord 37which is adapted for connection to a power source, which may be thehouse current supply. When the motor 34 is operating, air is drawn frombelow the assembly through a filter 38 that is supported between thelegs 33, as between angle strips 39 extending between the legs, anddirected toward the adjacent wall 13 of the cover 10.

Channeling of air from the blower housing 31 into the interior of thecover 10 may be effected in a variety of ways. However, a preferredarrangement is by means of a plastic slipcover 40 for the frame 32 whichcovers the top, back and sides of the frame, and which is provided witha hollow extension 40' from the open end of the blower housing 31 to anopening 41 in the wall 13 of the cover 10. As best seen in FIGURE 4, theend of the extension 40' of the slipcover is provided with an outwardlyextending lip or flange 42 which is fused to the wall 13.

Air from the blower is not permitted to gass horizontally through thewall 13. Rather, it is forced to travel upwardly :along the wall 13. Tothis end, I provide an elongated rectangular panel 45 which spans theopening 41, and which is fused to the inner surface of the wall 13 alongthe bottom and side edges of the panel 45. Additionally, the centerportion of the upper end of the panel 45 may be fused to the innersurface of the wall 13, as indicated at 46 in FIGURE 3.

As will be observed, air blown through the opening 31 strikes theconfronting surface of the panel 45 and, since the lower end of thepanel and the sides thereof are fused to the wall 13, the air forces thecenter portion of the panel 45 inwardly away from the wall 13, andthereby forces its way upwardly between the panel and the wall to escapepast the upper end of the panel 45 into the interior of the cover 10.

The panel 45 and the wall 13 effectively function as a one-way valve, toadmit air into the interior of the cover while the motor 34, isoperating, but preventing air from escaping back between the panel andthe wall when the motor is off. In this connection, the panel 45, islaid fiat against the inner surface of the wall 13 when it is fused inplace. Since the confronting surfaces of the panel 45 and the wall 13are smooth plastic, the surfaces tend to adhere to each other.Furthermore, when the motor 34 is turned off, air inside the cover 10presses against the inner wall of the panel 45 to urge it into intimateface-to-face contact with the confronting surface of the wall 13.Accordingly, when the motor 34 is turned off, the pressure will behigher in the enclosure than in the surrounding atmosphere; theconfronting faces of the panel 45 and the wall 13 are effectively sealedtogether, however, to prevent backfiow of air.

My invention includes means for automatically controlling the operationof the motor 34 so that it operates the blower to fill the interior ofthe cover 10, but is turned off when the cover is fully inflated. Afterthe cover is fully inflated, the motor operates the blower to add airwhenever necessary to keep it inflated, as when air pressure isdecreased upon opening the door 21.

Automatic operation of the motor and blower is effected through theswitch 35. The switch 35 preferably is a gravity-actuated switch, suchas the well known mercury type switch. The switch housing is pivotallymounted at 48 on the end of the blower housing 31, and an elongated rodor arm 49 is secured at one end to the switch housing and extendsthrough the slipcover 40 and alongside its extension 40 to a pointadjacent the wall 13. The switch 35 is adapted to operate so that it isin the off condition when the arm 49 is horizontally disposed, and is inthe on condition when the arm 49 is below the horizontal. FIGURE 10shows the Off condition.

The switch 35 may be of conventional construction in which contactterminals extending into the mercury capsule are connected to the motorleads 36 and the power cord 37. Thus, when the switch arm 43 is belowthe horizontal, the mercury flows into the portion of the capsule atwhich the contact terminals are located to effectively connect the powercord 37 to the motor leads 36, whereupon the motor 34 is set intooperation to cause the blower to force air into the interior of the poolcover. When the arm 49 reaches the horizontal position, the mercurycapsule is tilted to cause the mercury to move out of contact with thecontact terminals, whereupon the motor 34 stops.

As will be apparent, the arm 49 constitutes a weighted member extendingfrom the switch housing, and normally tends to tilt the switchdownwardly so that the mercury will establish contact between theterminals of the motor leads 36 and the cord 37. In accordance with myinvention, the arm 49 is allowed to remain below the horizontal whilethe pool cover 10 is being inflated, but is automatically raised to thehorizontal position when the pool cover reaches its optimum height,i.e., at an optimum pressurization just above atmospheric, preferablybetween about 0.1 to about 0.2 p.s.i. above atmospheric. For thispurpose, I arrange for the pool cover itself to raise the arm 49 to thehorizontal position when it is fully inflated. One way to accomplishthis, as illustrated in FIGURES 1 and 2, is to connect a flexible, butnot stretchable, cord 50 between the outer end of the arm 49 and themidpoint of the pool cover 10. Referring to FIGURES l, 5 and 6, areinforced plastic disc 51 is fused around its edge over the midpoint ofthe ceiling 12 of the pool cover. The disc 51 is provided with a pair ofopenings 52 in the center portion thereof, and the end of the cord 50 islooped through the openings and tied, as indicated at 54.

It will be helpful at this point to explain how the pool cover isinitially positioned over the pool and then inflated. It will beappreciated that the cover, being of plastic material, is folded andpacked for storage. Preparatory to inflating the cover, it is unfoldedand positioned over the pool, with the base tube 14 positioned aroundthe pool on the decking 15. The tube 14 is then filled with Water andcapped at 17, and the cover 40 for the blower assembly 33 is fitted overthe frame 32. At this time, the center portion of the pool coveroverlays the pool 11, and in fact lies in the water. Also the arm 49 isbelow the horizontal (by virtue of its weight) and the switch 35 istilted downwardly so that the mercury is in contact to establishelectrical connection between the motor leads 36 and the power cord 37.

With the door 21 closed, the power cord 37 is plugged into the powersource, and the motor 34 is immediately set into operation, whereuponair is forced into the interior of the pool cover as above described.The pool cover immediately starts inflating and the center portionthereof is lifted off the water and proceeds to rise. Air flowcontinues, and the pool cover continues to inflate, until it reaches itsfull height, at which time the cord 40 is extended to its full length,i.e., becomes taut, and the arm 49 is raised to the horizontal position.The motor then stops.

After the pool cover is thus fully inflated, the motor 34 will remainstopped until the volume of air within the cover decreases. If, forexample, the door 21 is opened by a person entering or leaving theinterior of the pool cover, some air will escape. Thereupon, the poolcover deflates slightly, allowing the cord 40 to slacken and permittingthe arm 49 to drop below the horizontal. Thereupon the motor 34 is setinto operation again, and air is supplied to make up the deficiency andagain inflate the pool cover to its maximum height, at which time thearm 49 is again pulled to the horizontal and the motor is stopped.

Regarding the switch 35, a mercury switch is ideally suited to preventoperation of the motor (after the cover 10 is fully inflated) untilthere is a significant loss of air. As will be appreciated, there issome volume change even when the door is closed, e.g., upon a suddentemperature decrease or with continuous evaporation of water from thepool. It is not desirable to have the motorcycle on and oif with everyminute loss of air. Since a mercury switch requires a definite movementto shift the mercury from one position to another, a few cubic feet ofair would have to be lost before the cord 40 would slacken sufficientlyand permit the arm 49 to lower sufficiently to set the motor intooperation.

The pool cover 10 is made of sufiicient size that persons entering theinterior thereof can readily stand erect near the wall 13, at asubstantial distance from the edge of the pool. Also, the ceilingportion 12 is sufiiciently high when the cover is infiated to allowample room for persons to dive off a board which may be mounted at oneend of the pool.

The above-described construction of my pool cover is one that willmaintain its position in fair weather and non-windy conditions. However,stability is insured, under adverse weather conditions, by providingmeans for anchoring the cover such that it cannot be dislodged orshifted, even in the presence of storms and high velocity Winds. To thisend, I provide a plurality of parallel strips 60 extending across theceiling portion 12, and preferably form the strips 60 of reinforcedplastic material (e.g., reinforced nylon) which are fused to the outersurface of the ceiling portion 12. Referring to FIGURES 1 and 7, eachstrip 60 at each end is formed with a flap bent back on itself and fusedto the body of thestrip, thereby forming a loop 61. The loop 61 isadapted to snugly receive a pin 62, and a line 63 is secured at one endaround the pin 62, as by being threaded through an opening in the strip60 above the loop 61.

At its lower end, the line 63 is secured to a pin 64 that is embedded inthe decking 15. Preferably, and as indicated in FIGURE 7, the pin 64does not extend above the decking, it is located in a small well 65formed in its surface.

Thus, the line 63 connecting the ends of the strips 60 and the pins inthe decking form tie lines or guy lines on the opposite sides of thepool cover it). The guy lines 63 follow the surface contour of the wall13 when the pool cover is fully inflated. With the pool cover thussupported on each side, it is effectively anchored to the decking andthereby stabilized, and will readily withstand winds of very highvelocities. The guy lines are of such a length that when the cover isfully inflated or even less than fully inflated, the guy lines are taut.The guy lines thus form ridges in the ceiling portion at the fullyinflated position of the cover.

The strips 60 need not be fused to the ceiling portion 12 in order tostabilize the cover 10 against high winds. However, it is preferable tofuse the strips 60 to the ceiling portion 12 in order to maintain apredetermined spacing between strips (for reasons hereinafter to bedetailed). As mentioned previously, contractions and expansion of thecover 16 take place frequently. If the strips 60 were not fused to theceiling portion 12, frictional engagement between the strips 60 and theceiling portion would occur with consequent wear and weakening of theceiling portion of the cover. Also, by fusing strips of reinforcingmaterial across the ceiling portion, if any tears should occur in theceiling, they will be localized between such strips 60.

For these reasons, it is preferable to fuse the strips 69 over asufficient portion of the ceiling so that the guy lines connect to theloops 61 of the strips 60 in a generally tangential manner with respectto the cover 10. (See FIGURE 7).

The spaced stabilizing strips 60 serve another very important functionin the control of pressure within the cover 10 itself. If the domedportion of the cover 10 were made of sheet vinyl plastic, withoutstabilizing means, such cover could expand greatly in hot weather. Forexample, the volume of air within the cover 10 could be twice as greaton a hot day compared to that on a cold day. Such expansion would causethe blower to turn off, and the internal pressure within the cover wouldwell be lower than the external pressure due to a sudden gust of wind.Thus, in the event of gusty conditions and hot weather, a domedenclosure made of sheet plastic alone may sag greatly, or even,collapse. With the use of stabilizing strips, such as strips 60, and guylines in combination therewith, the expansion between strips 60 spacedabout 6 apart is perhaps about 57% of what it would be in an unsupporteddome of 40 to 50" in length for the same weather conditions. Because thepressure excess in the enclosure or cover 19 is between 0.1-0.2 p.s.i.volume expansion of 57% will not cause any significant dcpressurizationwithin the cover 10.

As previously mentioned, the door 21 is adapted to be securely locked insealing relationship against the reinforced frame members 22, 24.Referring to FIGURE 9, the confronting edge portions of the reinforcingstrips 23, 24- are adapted to be stiffened, as by curved metal tubes 71,72 inserted therein. As shown, the tubes 71, 72 are arranged in slightlyoverlapping relation, and a curved strip 73 of soft plastic material issecured to the inner surface of the reinforced strip 23 of the door 21.The soft strip 73, which preferably is a sponge-like element, ispositioned so that a portion thereof is compressed between confrontingportions of the tubular members 71, 72 when the handle 25 is in theclosed position for latching the door. In this connection, the inner endof the handle 25 is shown to engage the bulge in the strip 24 caused bythe metal tube 72. In this manner, leakage of air around the closed dooris avoided.

Plastic enclosures of the type described herein, are absorbers of heat;and air, within the enclosure can, on a sunny day, become quite hot. Inorder to provide a ready and economical way of cooling the air withinthe enclosure, I provide the following:

The door 21 is maintained under a spring tension which normally urgesthe door inwardly but the force exerted by the spring is such that itdoes not overcome the normal pressurization within the enclosure (OJ-0.2p.s.i. above atmospheric) but exerts an inward force slightly less thanthe pressure exerted by the air within the enclosure. One such exampleof a suitable spring means is a pair of springs 80 which bias the door21 normally inwardly towards the door opening. See FIGURES 8 and 11especially. Of course, other modes of spring-loading the door 21 may beemployed.

The door 21, when left open, assumes a normal position just slightlyapart from the frame 22' 24, e.g., 1 to 2 inches. When the door is leftopen, the blower will work constantly, at its maximum capacity toprevent any deflection of the enclosure 10, and the air thuscontinuously blown into the cover 10, will escape through the slightlyopen door, and will very quickly result in a lowering of the temperatureof the air within the enclosure. When the air is sufiiciently cooled,the door need only be manually closed, and the blower will turn off onceproper pressure within the enclosure is reached.

From the foregoing, it will be apparent that various modifications canbe made in the structure illustrated and described herein withoutdeparting from the spirit and scope of my invention. Accordingly, I donot intend that my invention be limited, except as by the appendedclaims.

I claim:

1. An inflatable structure comprising:

a body member of foldable material having a rim adapted to releasablybut sealingly engage a surface over which the body member is to beinflated, said body member having an opening near said rim through whichto admit a gaseous fluid to raise the body member above the surface;

supply means to force gaseous fluid through said opening to inflate saidbody member;

control means operable from said body member to limit operation of saidsupply means when said body member is inflated;

a door opening in said body member;

a door having one edge thereof attached to an edge of said door opening;

means for sealingly engaging said door with said door opening in saidbody member; and

spring means in said door normally urging said door,

when unlocking, to a closed position when said blower is non-operative,said spring means being insufficient in force to close said door, whenunlocked, and when said blower is operative.

2- In combination:

a body of foldable plastic material having an integral tubular rim to beplaced adjacent an area to be enclosed, said rim being adapted to befilled with water to provide a weighted support base for the body, saidrim when filled with water having its lower surface forced into sealingcontact with said area to be enclosed, said body having an opening nearthe rim through which to force air beneath the body; and

a plastic flexible panel on the inner surface of said body, said panelcovering said opening and being fused along its lower and side edges tosaid inner surface, whereby air entering said opening is directed abovethe opening between the confrontation surfaces of said panel and thebody to escape past the upper endof said panel.

3. The structure of claim 2, including spaced, reinforced plastic stripsaflixed to the outer surface of said body, said strips extending acrossthe ceiling portion of said body, each of said strips being adapted tohave guy lines connected between each end thereof and the area adjacentsaid rim.

4. An inflatable structure to be placed on the deck ing around aswimming pool and inflated to provide a shelter within which persons canenjoy use of the pool, comprising:

a body of foldable plastic material having an integral tubular rim to beplaced on the decking around the pool, said rim being adapted to befilled with Water 8. to provide a weighted support base for the body,said rim when filled with water having its lower surface forced intosealing contact with the decking, said body having an opening near therim through which to force air into the body, said body also having adoor through which persons can enter and leave the body when it isinflated;

a blower assembly communicating with said opening and having a motor,said blower assembly including an elevated frame to be supported on thedecking adjacent the opening in said body, and a plastic slipcover oversaid frame having a tubular portion extending to said opening throughwhich to force air into said body;

a switch for connection to a power source and through which to effectoperation of the motor; and

means utilizing said body to control said switch so that the motoroperates the blower assembly while the body is being inflated, andthereafter to maintain a generally constant volume of air within thebody.

5. An inflatable structure to be placed on the decking or the like andinflated to provide a shelter comprising:

a body of foldable plastic material having an integral tubular rim to beplaced on the decking around the pool, said rim being adapted to befilled with water to provide a Weighted support base for the body, saidrim when filled with water having its lower surface forced into sealingcontact with the decking, said body having an opening near the rimthrough which to force air into the body, said body also having a doorthrough which persons can enter and leave the body when it is inflated;

a blower assembly communicating with said opening and having a motor,said lblower assembly including an elevated frame to be supported on thedecking adjacent the opening in said body, and a plastic slipcover oversaid frame having a tubular portion extending to said opening throughwhich to force air into said body;

a plastic panel on the inner surface of said body, said panel coveringsaid opening and being fused along its lower and side edges to saidinner surface, whereby air entering said opening is directed above theopening between the confronting surfaces of said panel and body toescape past the upper end of said panel;

a switch for connection to a power source and through which to effectoperation of the motor; and

means utilizing said body to control said switch so the motor operatesthe blower assembly while the body is inflated, and thereafter when thevolume of air within the body decreases.

6. An inflatable structure, inflatable by gaseous fluid from a fluidsupply source, maintained in a substantially static fully inflatedposition comprising:

stabilizing means extending over said inflatable structure when inflatedto substantially prevent said inflatable structure from moving generallyupwardly from a desired fully inflated position, said stabilizing meansincluding a plurality of spaced reinforcing non-elastic andsubstantially non-stretchable strips of material, each affixed to atleast a portion of the surface of said inflatable structure and held toa base adjacent said body member; and

control means to limit the flow of gaseous fluid from said fluid supplysource into said inflatable structure when said inflatable structure isin said fully inflated position and to increase the flow of gaseousfluid from said fluid supply source into said inflatable structure whensaid inflatable structure starts to deflate from said fully inflatedposition, said control means including means affixed to said inflatablestructure which moves as a result of movement of a finite area betweensaid reinforcing strips, said control means and said stabilizing meansco-acting to maintain said inflatable structure in a substantiallystatic position.

7. The means of claim 6 wherein said reinforcing strips are flexible tofollow the curvature of said inflatable structure.

8. The means of claim 6 wherein said stabilizing means comprises aplurality of spaced reinforcing strips extending over said inflatablestructure whereby when said structure is inflated the ends of saidreinforcing strips are adapted to be anchored to the ground adjacentsaid inflatable structure by guy wire means.

9. The means of claim 6 wherein said reinforcing strips are strips areplastic and are fused to at least a portion of said surface of saidinflatable structure.

10. The means of claim 6 wherein said reinforced strips are reinforcednylon.

11. An inflatable structure comprising:

a body member of foldable material having a rim adapted to releasablybut sealingly engage a surface over which the body member is to beinflated, said body member having a roof section and having an openingthrough which to admit a gaseous fluid to raise the body member abovethe surface;

supply means to force gaseous fluid through said opening to inflate saidbody member;

stabilizing means extending over said body member when inflated tosubstantially prevent said body member from moving upwardly from itsfully inflated .position, said stabilizing means including a pluralityof spaced reinforcing non-elastic substantially non-stretchable stripsof material, each aflixed to at least a portion of the surface of saidbody member and adapted to be held taut at the ground adjacent said bodymember; and

control means to limit the flow of gaseous fluid from a fluid supplysource into said inflatable structure when said body member is inflatedand to increase the flow of gaseous fluid from said fluid supply sourceinto said inflatable structure when said body member starts to deflate,said control means including means aflixed to said inflatable structurewhich moves as a result of movement of a finite area between saidreinforcing strips, said control means and said stabilizing meansco-acting to maintain said body member in a substantially staticposition.

12. The inflatable structure of claim 11 wherein said control meansincludes a cable means which is aflixed to the apex of the finite areacentrally disposed between a pair of reinforcing strips on said bodymember.

13. The inflatable structure of claim 11 wherein said strips of saidstabilizing means are flexible.

14. The inflatable structure of claim 11 wherein said control meanscomprises (a) a flexible, non-stretchable cable, (-b) a switch arm and(c) a switch operably connected to said supply means, said cable fixedlyattached at one end to said finite area between said reinforcing stripsand fixedly attached at the other end to said switch arm, said cablehaving a length such that said cable moves said switch arm to the offposition when said reinforcing strips are fully extended and such thatsaid cable moves said switch arm towards the on position when saidreinforcing strips are less than fully extended to closely control theflow of said gaseous fluid into said body member from said supply means,whereby movement of said body member from its fully inflated position issubstantially limited.

15. An inflatable structure comprising in combination:

a body member of foldable material having a rim adapted to releasablybut sealingly engage a surface over which the body member is to beinflated, said body member having a roof section and having an openingthrough which to admit a gaseous fluid to raise the body member abovethe surface;

supply means to force gaseous fluid through said opening to inflate saidbody member; stabilizing means extending over said body member wheninflated to substantially prevent said body member from moving upwardlyfrom its fully inflated position, said stabilizing means including aplurality of flexible and non-elastic and substantially nonstretchablespaced reinforcing strips of material, each aflixed to a portion of thesurface of said body member and held at the ground adjacent said bodymemher, said stabilizing means substantially inhibiting further upwardmovement of said body member from a desired fully inflated position; and

control means co-acting with said stabilizing means to stop flow ofgaseous fluid supplied by said supply means to said inflatable structurewhen said body member reaches said fully inflated position and tocommence flow of gaesous fluid by said supply means to said inflatablestructure when said body member deflates from said fully inflatedposition, said control means comprising (a) a flexible non-stretchablecable, (b) a switch arm and (c) a switch operably connected to saidsupply means, said cable fixedly attached at one end to said finite areabetween said reinforcing strips and fixedly attached at the other end tosaid switch arm, said cable having a length such that said cable movessaid switch arm to the off position when said reinforcing strips arefully extended and such that said cable moves said switch arm towardsthe on position when said reinforcing strips are less than fullyextendedto closely control the flow of said gaseous fluid into said body memberfrom said supply means, whereby movement of said body member from itsfully inflated position is substantially limited.

16. The means of claim 15 wherein said stabilizing means comprises aplurality of spaced reinforced plastic strips extending over saidinflatable structure when inflated, the ends of said plastic stripsconnected to guy wires and the other ends of said guy wires anchored tothe ground adjacent said inflatable structure such that said guy wiresare taut when said inflatable structure is fully inflated.

References Cited UNITED STATES PATENTS 2,948,286 8/1960 Turner 5222,988,096 6/1961 Otto 1 2,990,837 7/1961 Cushman 52-2 FOREIGN PATENTS3,059,655 10/1962 Belgium.

REINALDO P. MACHADO, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No.3,353,309 November 21, 1967 John P. Kwake It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 9, line 13, strike out "are strips".

Signed and sealed this 3rd day of December 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

1. AN INFLATABLE STRUCTURE COMPRISING: A BODY MEMBER OF FOLDABLEMATERIAL HAVING A RIM ADAPTED TO RELEASABLY BUT SEALINGLY ENGAGE ASURFACE OVER WHICH THE BODY MEMBER IS TO BE INFLATED, SAID BODY MEMBERHAVING AN OPENING NEAR SAID RIM THROUGH WHICH TO ADMIT A GASEOUS FLUIDTO RAISE THE BODY MEMBER ABOVE THE SURFACE; SUPPLY MEANS TO FORCEGASEOUS FLUID THROUGH SAID OPENING TO INFLATE SAID BODY MEMBER; CONTROLMEANS OPERABLE FROM SAID BODY MEMBER TO LIMIT OPERATION OF SAID SUPPLYMENS WHEN SAID BODY MEMBER IS INFLATED; A DOOR OPENING IN SAID BODYMEMBER; A DOOR HAVING ONE EDGE THEREOF ATTACHED TO AN EDGE OF SAID DOOROPENING;